During internal surgery it is often necessary to alter the position of various organs or tissues to provide access to the tissues which are the subject of the surgery. It is also necessary to hold the organs or tissues which have been so moved in a stable position during the surgery so that movement thereof will not interfere with the work of the surgeon or surgical assistants.
Devices which move and hold viscera for this purpose are referred to as surgical retractors because of their function of retracting the interfering tissues from the operating field. A number of such devices exist for use where a relatively large incision has been made in the subject's body. Often these devices have broad surfaces to distribute the forces they exert on the viscera over larger areas and thus minimize trauma. One such retractor is shown in U.S. Pat. 4,889,107. Another such retractor is the Richardson Retractor manufactured by Walter Lorenz Surgical Instruments, Inc. of Jacksonville, Fla. Both these devices are inserted through large incisions which makes them unsuitable for laparoscopic surgery.
In laparoscopic surgery only small incisions are made, thereby minimizing trauma and post-operative pain. An endoscope is used to illuminate the internal organs and tissues and provide the surgeon with visual feedback which may be magnified and displayed optically and electronically. Surgical instruments are introduced through flexible tubes, trocars or the operating sheath of an endoscope, which may be only one (1) centimeter in diameter, and are remotely manipulated by the surgeon.
Conventional retractors are too large to enter the body through the small incisions made during laparoscopic surgery and in some cases may be disproportionate in size to the tissues to be retracted. Accordingly it is common during laparoscopic surgery to retract tissues using very small forceps to push or pull the tissues, which increases the risk of injury or trauma. In some instances, a camera held in place by trocar may be used to push tissue or organs such as the transverse colon away from the surgical site during laparoscopic surgery. However, the camera tends to get hot and may damage or even perforate the tissue with which the camera is in contact. Thus, it is desireable to develop a laparoscopic retractor which does not damage the retracted tissue.
Inflatable or collapsible devices or balloons have been used in surgery or body treatment for various purposes. A surgical retractor for conventional surgery which collapses for ease of removal just before final closure is shown in U.S. Pat. 3,863,639. Balloons have also been inserted in the body for a variety of large scale applications such as opening passageways, as seen in U.S. Pat. Nos. 4,312,353; 4,714,074; 4,800,901 and 4,899,747. One inflatable device for use in propelling an endoscope through a body passage is shown in U.S. Pat. 4,207,872.